In an office environment windows can be opened and
closed mechanically, controlled by an environmental
management system.

Stack Ventilation takes this a stage further, cool air
is brought in at low level and warm air is removed at
high level.

In the image below, fresh air enters through windows
on each floor and the stale warmer air rises through the
atrium to the glazed roof, where electrically powered
actuators open windows to vent the atrium. In this
situation this was connected to a smoke detection system
which could manually override and open in the event of a
fire.

Mechanical Ventilation

Heat recovery systems can provide an energy efficient
means to heat and ventilate a building particularly in
combination with an air tight construction. These
provide warm filtered air to the habitable parts of the
building whilst removing stale air from humid areas.

A series of ducts extract stale moist air from
kitchens, bathrooms and utilities which is then passed
through the MVHR unit and ducted to the outside. Fresh
air is brought from outside to the MVHR unit where the
heat from the stale air is transferred to it before it
is ducted to the habitable areas.

Correct specification of the whole system can have an
impact on its efficiency